The applications of diagnostic “X” ray radiation are well known in medical sciences. However, there is an always need to overcome the health hazards due to radiations by utilizing appropriate radiation shielding materials.
The conventional shielding materials are made using a) lead which is toxic and otherwise also possess many other important applications e.g. lead acid battery, b) barite which is relatively costly and contains deleterious impurities and c) hematite ore useful for making iron metal. All the three conventional shielding materials namely lead, barite and hematite ore are non-replinshable commodities. Further, the conventional shielding materials possess limited functionality.
In view of above, there is an urgent need to develop advanced radiation shielding materials possessing additional functionality e.g. a) fire resistance, b) heat resistance, c) mold ability and flexibility to the developed material by, employing appropriate novel matrixes for the fabrication of lead, barium and hematite ore free advanced radiation shielding material utilizing red mud based “Nano” gel type material.
The so far known conventional and advanced shielding materials developed till date, utilizes lead, barium and hematite ore based compounds as raw materials and depend on involvement of cumbersome and energy intensive process. Further the use of conventional matrixes limits the functionality aspects which are otherwise very much necessary to face the challenges of new millennium. Conventional polymeric matrixes used in making shielding material are not durable and therefore are prone to health hazard over the years.
In view of above there is an urgent need to develop advanced non-toxic Lead, Barium and Hematite ore free, red mud based “Nano” gel type material useful for making, functional radiation shielding materials utilizing appropriate novel matrixes. The novel matrixes used are 1) Advanced Geopolymer matrix, 2) Advanced geo polymeric matrix, 3) Advanced putty and cement matrix, 4) Advance phosphatic material based matrix, 5) Apart from these novel matrixes the material is also compatible with conventional matrixes, however with the limited functionality as against novel matrixes.
To this end a novel process for making advanced Lead, Barium and Hematite ore free, “Nano” gel, based non-toxic, functional radiation shielding materials has been developed utilizing industrial waste red mud generated in large quantity all over the world in Aluminum producing industries. The developed process is highly energy efficient and environment friendly.
The novel process involves the appropriate physico-chemical consolidation and or densification of red mud using advanced or conventional matrix helps in obtaining functional radiation shielding material. Red mud is an industrial Waste generated in aluminum industry containing 8-10% silica, 28-31% iron oxide, 20-24% alumina, 19-21% titanium oxide, 6-7% sodium oxide and 4-5% calcium oxide. The novel process involves simultaneous and synergistic chemical reactions of various mineralogical and chemical compounds like hematite, anatse, rutile, gibbsite and cancraite of red mud with complementary various chemical compounds present in citrus fruit wastes (namely orange peel waste, lemon peel waste etc.) like cellulose, hemicellulose, pectin and especially citric acid to form nano gel material to obtain the fine “tailored shielding powder” useful for making functional radiation shielding materials using various appropriate matrixes.
The genus Citrus comprises of about 140 genera and 1,300 species and belongs to the Rutaceae or Rue family, and majorly includes Some important fruits like Citrus sinensis (Orange), Citrus paradisi (Grapefruit), Citrus limon (Lemon), Citrus reticulata (tangerine), Citrus grandis (shaddock), Citrus aurantium (sour orange), Citrus medica (Citron), and Citrus aurantifolia (lime). Citrus are well known as one of the world's major fruit crops that are produced in many countries with tropical or subtropical climate. Brazil, USA, Japan, China, Mexico, Pakistan, and countries of the Mediterranean region, are the major Citrus producers. Worldwide, Citrus production is estimated to be at levels as high as 105 million metric tons (MMT) per annum, Brazil being the largest producer with contribution of 19.2 MMT followed by the United States. Further, the citrus peel waste is generates from the processing of citrus fruit, constituting cellulose, hemicellulose, pectin and especially citric acid. The citrus peel waste is highly biodegradable, produced worldwide and therefore its disposal has become major environmental concern.
Further apart from achieving technological and functional characteristics in the developed “Advanced non-toxic Lead, Barium and hematite ore free, functional radiation shielding materials, “the process is simple, highly energy efficient, environmental friendly and is also highly cost effective and therefore enabling wide spread utilization of developed material for broad application spectrum ranging from diagnostic radiation installations such as diagnostic X-ray room to CT scanner room etc.
Reference may be made to article “Development of high performance gel type radiation shielding material using polymer resin by Naotero Odano etal. In Progress in nuclear science and technology vol. 4 (2014) pp. 639-642, wherein new gel type shielding material mainly consist of conventional resin, lead powder and boron compound was developed. The drawback of the process is use of toxic lead for the preparation of gel type radiation shielding material.
Reference may be made to patent, Radiation shielding material and method of making same by Rosensweig Alan and Tashlick Irving, U.S. Pat. No. 3,437,602 wherein Radiation shielding material have been developed using hematite ore. The drawback of the process leads to the formation of in-homogeneous radiation shielding matrix.
Reference may be made to patent, low temperature process for making radiaopac materials utilizing industrial/agricultural waste as raw material by S.S Amritphale et al., wherein low temperature process for making radiaopac materials have been disclosed. The drawback of the process is making shielding material by a) sintering in the temperature range of 900-1300° C. and b) need of barium based compounds.
Further, from the hitherto reported prior art it is clear that “Advanced non-toxic Lead, Barium and hematite ore free, Red Mud based “Nano” gel type material useful for making, functional radiation shielding materials utilizing appropriate novel matrixes has not been pursued at all. From the hitherto reported prior art and based on the drawbacks of the known process, the various issues that need to be addressed and problems to be solved for making highly value Advanced non-toxic Lead, Barium and hematite ore free, Red Mud based “Nano” gel type material useful for making, functional radiation shielding materials and also ensuring total utilization of red mud are summarized here as under:—
1) The use of toxic lead for the preparation of gel type shielding materials.
2) The need of use of conventional hematite and barite for making shielding materials.
3) The need of high temperature sintering in the temperature range of 900-1300° C. for making shielding materials.